Optical imaging system, imaging apparatus and electronic device

ABSTRACT

An optical imaging system includes, in order from an object side to an image side: a first lens element having positive refractive power, a second lens element having negative refractive power, a third lens element, a fourth lens element, a fifth lens element having both an object-side surface and an image-side surface being aspheric, and a sixth lens element having both an object-side surface and an image-side surface being aspheric, wherein the optical imaging system has a total of six lens elements; at least one lens element among the first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element, and the sixth lens element has at least one inflection point.

RELATED APPLICATIONS

This application is a Continuation Application of U.S. application Ser.No. 15/364,834, filed on Nov. 30, 2016, now approved and claims priorityto Taiwan Application Serial Number 105126726, filed on Aug. 22, 2016,which is incorporated by reference herein in its entirety.

BACKGROUND Technical Field

The present disclosure relates to an optical imaging system and animaging apparatus, and more particularly, to an optical imaging systemand an imaging apparatus applicable to electronic devices.

Description of Related Art

As camera modules being widely utilized, the applications of the cameramodules for various intelligent electronics, car devices, recognitiondevices, entertainment devices, sports devices and smart home systemshave become a development trend in the technology. Meanwhile, in orderto enrich users' experiences, smart devices with one, two or even morethan three lens assemblies are becoming the mainstream in the market andthus lens assemblies with different features to meet requirements indifferent applications are continuously in development.

Currently available compact lens assemblies for the electronic productsoften have features like wide view angle and short object distance.However, the optical designs of such lens assemblies failed to meet theconsumers' various demands in photo shooting. Conventional opticalsystems usually use multi-piece structure with spherical glass lenses,which results in having an overly large size of the lens assemblies.Meanwhile, costs of such lens assemblies are also too high to be appliedin various devices and products. Therefore, the conventional opticalsystems have failed to meet the current trend of the technologydevelopment.

SUMMARY

According to one aspect of the present disclosure, an optical imagingsystem, comprising, in order from an object side to an image side: afirst lens element having positive refractive power; a second lenselement having negative refractive power; a third lens element; a fourthlens element; a fifth lens element having both an object-side surfaceand an image-side surface being aspheric; and a sixth lens elementhaving both an object-side surface and an image-side surface beingaspheric, wherein the optical imaging system has a total of six lenselements; at least one lens element among the first lens element, thesecond lens element, the third lens element, the fourth lens element,the fifth lens element, and the sixth lens element has at least oneinflection point; a sum of axial distances between every two adjacentlens elements of the optical imaging system is ΣAT, an axial distancebetween the third lens element and the fourth lens element is T34, afocal length of the first lens element is f1, a focal length of thethird lens element is f3, an axial distance between an object-sidesurface of the first lens element and an image surface is TL, anentrance pupil diameter of the optical imaging system is EPD, and thefollowing conditions are satisfied:1.05<ΣAT/T34<4.0;|f1/f3|<1.0;1.0<TL/EPD<1.90.

According to another aspect of the present disclosure, an opticalimaging system, comprising, in order from an object side to an imageside: a first lens element having positive refractive power; a secondlens element having negative refractive power; a third lens element; afourth lens element; a fifth lens element having both an object-sidesurface and an image-side surface being aspheric; and a sixth lenselement having both an object-side surface and an image-side surfacebeing aspheric, the image-side surface being concave in a paraxialregion thereof, and at least one convex shape in an off-axial region onthe image-side surface thereof, wherein the optical imaging system has atotal of six lens elements; a sum of axial distances between every twoadjacent lens elements of the optical imaging system is ΣAT, an axialdistance between the third lens element and the fourth lens element isT34, a central thickness of the first lens element is CT1, a centralthickness of the second lens element is CT2, a central thickness of thethird lens element is CT3, a central thickness of the fourth lenselement is CT4, a central thickness of the fifth lens element is CT5, acentral thickness of the sixth lens element is CT6, and the followingconditions are satisfied:1.10<ΣAT/T34<1.80;0.10<(CT2+CT3+CT4+CT5)/(CT1+CT6)<1.20.

According to another aspect of the present disclosure, an imagingapparatus includes the aforementioned optical imaging system and animage sensor disposed on an image surface of the optical imaging system.

According to yet another aspect of the present disclosure, an electronicdevice includes the aforementioned imaging apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic view of an imaging apparatus according to the 1stembodiment of the present disclosure;

FIG. 1B shows longitudinal spherical aberration curves, astigmatic fieldcurves and a distortion curve of the imaging apparatus according to the1st embodiment;

FIG. 2A is a schematic view of an imaging apparatus according to the 2ndembodiment of the present disclosure;

FIG. 2B shows longitudinal spherical aberration curves, astigmatic fieldcurves and a distortion curve of the imaging apparatus according to the2nd embodiment;

FIG. 3A is a schematic view of an imaging apparatus according to the 3rdembodiment of the present disclosure;

FIG. 3B shows longitudinal spherical aberration curves, astigmatic fieldcurves and a distortion curve of the imaging apparatus according to the3rd embodiment;

FIG. 4A is a schematic view of an imaging apparatus according to the 4thembodiment of the present disclosure;

FIG. 4B shows longitudinal spherical aberration curves, astigmatic fieldcurves and a distortion curve of the imaging apparatus according to the4th embodiment;

FIG. 5A is a schematic view of an imaging apparatus according to the 5thembodiment of the present disclosure;

FIG. 5B shows longitudinal spherical aberration curves, astigmatic fieldcurves and a distortion curve of the imaging apparatus according to the5th embodiment;

FIG. 6A is a schematic view of an imaging apparatus according to the 6thembodiment of the present disclosure;

FIG. 6B shows longitudinal spherical aberration curves, astigmatic fieldcurves and a distortion curve of the imaging apparatus according to the6th embodiment;

FIG. 7A is a schematic view of an imaging apparatus according to the 7thembodiment of the present disclosure;

FIG. 7B shows longitudinal spherical aberration curves, astigmatic fieldcurves and a distortion curve of the imaging apparatus according to the7th embodiment;

FIG. 8 is a schematic view showing the distance represented by theparameter Yc62 of an optical imaging system of the present disclosure;

FIG. 9 is a schematic view showing an imaging apparatus with atriangular prism of the present disclosure;

FIG. 10 is a perspective view of the triangular prism shown in FIG. 9.

FIG. 11A shows a smartphone with an imaging apparatus of the presentdisclosure installed therein;

FIG. 11B shows a tablet with an imaging apparatus of the presentdisclosure installed therein;

FIG. 11C shows a wearable device with an imaging apparatus of thepresent disclosure installed therein;

FIG. 12A shows a rear view camera with an imaging apparatus of thepresent disclosure installed therein;

FIG. 12B shows a driving recording system with an imaging apparatus ofthe present disclosure installed therein; and

FIG. 12C shows a surveillance camera with an imaging apparatus of thepresent disclosure installed therein.

DETAILED DESCRIPTION

The present disclosure provides an optical imaging system including, inorder from an object side to an image side, a first lens element, asecond lens element, a third lens element, a fourth lens element, afifth lens element, and a sixth lens element.

The first lens element has positive refractive power to provide thesystem with the main light convergent ability for lens miniaturization.

The second lens element has negative refractive power. The second lenselement may have an object-side surface being concave and an image-sidesurface being convex such that the aberrations caused by the first lenselement can be balanced so as to control the image quality.

The third lens element may have an object-side surface being convex andan image-side surface being concave so as to enhance the astigmatismcorrecting ability of the system.

The fifth lens element has both an object-side surface and an image-sidesurface being aspheric and may have negative refractive power so as tobalance chromatic aberrations and control the back focal length forvarious applications. The fifth lens element may have the object-sidesurface being concave so as to balance the aberrations of the system.The fifth lens element may have the image-side surface being concave soas to help the sixth lens element control the back focal length for theminiaturization of the lens assembly.

The sixth lens element has both an object-side surface and an image-sidesurface being aspheric and may have positive refractive power so as tofavorably control angle of view to meet the common application range.The sixth lens element may have the object-side surface being convex soas to coordinate the configuration of the system to enhance theaberration correcting ability of the sixth lens element. The sixth lenselement may have the image-side surface being concave in a paraxialregion thereof and at least one convex shape in an off-axial region onthe image-side surface thereof so as to reduce the back focal length forcompactness of the lens assembly.

The optical imaging system has a total of six lens elements; at leastone lens element among the first lens element, the second lens element,the third lens element, the fourth lens element, the fifth lens element,and the sixth lens element has at least one inflection point such thatthe total track length of the system can be reduced while theaberrations in an off-axial region can be effectively corrected so as toprovide satisfactory image quality in a peripheral region.

When a sum of axial distances between every two adjacent lens elementsof the optical imaging system is ΣAT, an axial distance between thethird lens element and the fourth lens element is T34, and the followingcondition is satisfied: 1.05<ΣAT/T34<4.0, the spatial arrangement can beeffectively controlled so as to improve the symmetry and the imagequality of the system. Preferably, the following condition can besatisfied: 1.10<ΣAT/T34<2.50. Preferably, the following condition can besatisfied: 1.10<ΣAT/T34<1.80.

When a focal length of the first lens element is f1, a focal length ofthe third lens element is f3, and the following condition is satisfied:|f1/f3|<1.0, the controlling ability at the object side of the systemcan be strengthened so as to be suitable for a better shooting range.Preferably, the following condition can be satisfied: |f1/f3|<0.70.

When an axial distance between an object-side surface of the first lenselement and an image surface is TL, an entrance pupil diameter of theoptical imaging system is EPD, and the following condition is satisfied:1.0<TL/EPD<1.90, the amount of incident light can be increased forimproved image brightness while controlling the total track length ofthe system effectively to avoid an overly large size of the device.

When a central thickness of the first lens element is CT1, a centralthickness of the second lens element is CT2, a central thickness of thethird lens element is CT3, a central thickness of the fourth lenselement is CT4, a central thickness of the fifth lens element is CT5, acentral thickness of the sixth lens element is CT6, and the followingcondition is satisfied: 0.10<(CT2+CT3+CT4+CT5)/(CT1+CT6)<1.20, thestructural strength of the lens element at an outer side of the lensassembly can be increased so as to be suitable for various environments.Preferably, the following condition can be satisfied:0.20<(CT2+CT3+CT4+CT5)/(CT1+CT6)<0.75.

When a focal length of the optical imaging system is f, the entrancepupil diameter of the optical imaging system is EPD, and the followingcondition is satisfied: 1.0<f/EPD<1.55, the system can obtain a largeaperture so as to improve the light coverage of the lens elements ateach field of view and further increase the amount of light retrieved bythe system and the image brightness effectively.

When an Abbe number of the first lens element is V1, an Abbe number ofthe second lens element is V2, an Abbe number of the third lens elementis V3, an Abbe number of the fourth lens element is V4, an Abbe numberof the fifth lens element is V5, an Abbe number of the sixth lenselement is V6, and the following condition is satisfied:0.20<(V2+V4+V6)/(V1+V3)<0.80, the focal planes at different wavelengthscan coincide so as to favorably correct the axial chromatic aberration.When the following condition is satisfied: 0.30<(V4+V5+V6)/(V1+V3)<0.95,the lens elements in the system can be favorably coordinated with ahigher degree of freedom in optimizing the shape geometry of the lenselements so as to preferably achieve a better balance of theaberrations.

When a half of a maximal field of view of the imaging capturing lensassembly is HFOV, and the following condition is satisfied:0.20<tan(HFOV)<0.50, the requirements for general applications can befavorably satisfied so as to obtain a more suitable imaging range.

When a curvature radius of the object-side surface of the sixth lenselement is R11, a curvature radius of the image-side surface of thesixth lens element is R12, and the following condition is satisfied:−0.10<(R11−R12)/(R11+R12)<0.35, the geometry and the refractive power ofthe sixth lens element can be effectively controlled such that the sixthlens element becomes a correction lens to enhance its aberrationcorrecting ability.

When a curvature radius of the image-side surface of the third lenselement is R6, a curvature radius of an object-side surface of thefourth lens element is R7, and the following condition is satisfied:−2.0<(R6+R7)/(R6−R7)<0, the symmetry of the system can be improved whilethe system controlling ability at the object side and the aberrationcorrecting ability at the image side can be strengthened.

When an axial distance between the image-side surface of the sixth lenselement and the image surface is BL, a central thickness of the firstlens element is CT1, and the following condition is satisfied:0.20<BL/CT1<0.90, the structural strength at the object side can beincreased while the back focal length can be controlled so as to reducethe size.

When a vertical distance between a maximum effective diameter positionon the object-side surface of the first lens element and an optical axisis Y11, a maximum image height of the optical imaging system is ImgH,and the following condition is satisfied: 0.65<Y11/ImgH<1.0, theincident light range of the system can be effectively controlled so asto improve image brightness and image quality.

When the focal length of the optical imaging system is f, the axialdistance between the object-side surface of the first lens element andthe image surface is TL, and the following condition is satisfied:0.80<f/TL<1.10, the angles of views and the total track length of thesystem can be balanced and suitable for different applications.

When an entrance pupil diameter of the optical imaging system is EPD, amaximum image height of the optical imaging system is ImgH, and thefollowing condition is satisfied: 1.15<EPD/ImgH<2.0, the lightretrieving areas can be effectively increased such that the image can bebrighter and clearer. Preferably, the following condition can besatisfied: 1.30<EPD/ImgH<1.80.

When a vertical distance between a maximum effective diameter positionon the object-side surface of the first lens element and an optical axisis Y11, a vertical distance between a maximum effective diameterposition on the image-side surface of the sixth lens element and theoptical axis is Y62, and the following condition is satisfied:0.80<Y11/Y62<1.35, the sizes of the lens elements can be balanced so asto increase the symmetry of the lens assembly and favor the bearing andlapping between the lens elements.

Please refer to FIG. 8. When a vertical distance between an off-axialcritical point on the image-side surface of the sixth lens element (L6)and the optical axis is Yc62, the focal length of the optical imagingsystem is f, and the following condition is satisfied: 0.05<Yc62/f<0.70,angles of the light at a peripheral region can be favorably controlledso as to correct aberrations in an off-axial region.

When a curvature radius of the object-side surface of the first lenselement is R1, the central thickness of the first lens element is CT1,and the following condition is satisfied: 0.70<R1/CT1<1.50, thethickness and the curvature configuration of the first lens element canbe balanced so as to improve the system stability.

When the axial distance between the object-side surface of the firstlens element and the image surface is TL, and the following condition issatisfied: 3.0 mm<TL<7.0 mm, the total track length of the system can beeffectively controlled so as to favor the miniaturized design.

The optical imaging system may further comprise an aperture stop. Whenthe axial distance between the object-side surface of the first lenselement and the image surface is TL, an axial distance between theaperture stop and the image surface is SL, and the following conditionis satisfied: 0.65<SL/TL<0.85, the positioning of the aperture stop canbe balanced so as to effectively control view angles while adjusting theincident angle of the image surface and increasing the image brightnessfor a wider range of applications.

Please refer to FIG. 9. As shown in the figure, the optical imagingsystem of the present disclosure may further comprise a reflectivecomponent PR at the object side of the first lens element along theoptical axis such that the direction of the optical axis can beeffectively controlled and the spatial arrangement of the system can bemore flexible to meet different requirements. The reflective componentPR can be a mirror or a prism. Please refer to FIG. 10. When thereflective component PR is a triangular prism; a height of thetriangular prism is H, a length of a ramp of the triangular prism is D,and the following condition is satisfied: 0.90<H/D<1.35, the prism canbe kept in the smallest volume without modifying the imaging conditions.

According to the optical imaging system of the present disclosure, thelens elements thereof can be made of glass or plastic material. When thelens elements are made of glass material, the distribution of therefractive power of the optical imaging system may be more flexible todesign. When the lens elements are made of plastic material, themanufacturing cost can be effectively reduced. Furthermore, surfaces ofeach lens element can be arranged to be aspheric (ASP). Since theseaspheric surfaces can be easily formed into shapes other than sphericalshapes so as to have more controllable variables for eliminatingaberrations and to further decrease the required quantity of lenselements, the total track length of the optical imaging system can beeffectively reduced.

According to the optical imaging system of the present disclosure, theoptical imaging system can include at least one stop, such as anaperture stop, a glare stop or a field stop, so as to favorably reducethe amount of stray light and thereby improving the image quality.

According to the optical imaging system of the present disclosure, anaperture stop can be configured as a front stop or a middle stop. Afront stop disposed between an imaged object and the first lens elementcan provide a longer distance between an exit pupil of the opticalimaging system and the image surface so that the generated telecentriceffect can improve the image-sensing efficiency of an image sensor, suchas a CCD or CMOS sensor. A middle stop disposed between the first lenselement and the image surface is favorable for enlarging the field ofview of the optical imaging system, thereby providing the opticalimaging system with the advantage of a wide-angle lens.

According to the optical imaging system of the present disclosure, whenthe lens element has a convex surface and the region of convex shape isnot defined, it indicates that the surface can be convex in the paraxialregion thereof. When the lens element has a concave surface and theregion of concave shape is not defined, it indicates that the surfacecan be concave in the paraxial region thereof. Likewise, when the regionof refractive power or focal length of a lens element is not defined, itindicates that the region of refractive power or focal length of thelens element can be in the paraxial region thereof.

According to the optical imaging system of the present disclosure, theimage surface of the optical imaging system, based on the correspondingimage sensor, can be a plane or a curved surface with an arbitrarycurvature, especially a curved surface being concave facing towards theobject side.

The optical imaging system of the present disclosure can be optionallyapplied to moving focus optical systems. According to the opticalimaging system of the present disclosure, the optical imaging systemfeatures a good correction capability and high image quality, and can beapplied to 3D (three-dimensional) image capturing applications andelectronic devices, such as digital cameras, mobile devices,smartphones, digital tablets, smart TVs, network surveillance devices,motion sensing game consoles, driving recording systems, rear viewcamera systems, drone cameras and wearable devices.

According to the present disclosure, an imaging apparatus includes theaforementioned optical imaging system and an image sensor, wherein theimage sensor is disposed on or near an image surface of the opticalimaging system. Therefore, the design of the optical imaging systemenables the imaging apparatus to achieve the best image quality.Preferably, the optical imaging system can further include a barrelmember, a holder member or a combination thereof. Also, the imagingapparatus can further include an optical image stabilizer (OIS) tocoordinate with the optical imaging system so as to provide a betterimaging quality.

Please refer to FIG. 11A, FIG. 11B and FIG. 11C, an imaging apparatus1101 may be installed in an electronic device including, but not limitedto, a smartphone 1110, a tablet 1120, or a wearable device 1130. Pleaserefer to FIG. 12A, FIG. 12B and FIG. 12C, an imaging apparatus 1201 maybe installed (optionally with a display screen 1202) in an electronicdevice including, but not limited to, a rear view camera 1210, a drivingrecording system 1220, or a surveillance camera 1230. The aforementionedexemplary figures of different electronic devices are only exemplary forshowing the imaging apparatus of the present disclosure installed in anelectronic device, and the present disclosure is not limited thereto.Preferably, the electronic device can further include a control unit, adisplay unit, a storage unit, a random access memory unit (RAM) or acombination thereof.

According to the above description of the present disclosure, thefollowing 1st-7th specific embodiments are provided for furtherexplanations.

1st Embodiment

FIG. 1A is a schematic view of an imaging apparatus according to the 1stembodiment of the present disclosure. FIG. 1B shows, in order from leftto right, longitudinal spherical aberration curves, astigmatic fieldcurves and a distortion curve of the imaging apparatus according to the1st embodiment.

In FIG. 1A, the imaging apparatus includes an optical imaging system(not otherwise herein labeled) of the present disclosure and an imagesensor 190. The optical imaging system includes, in order from an objectside to an image side, a first lens element 110, an aperture stop 100, asecond lens element 120, a third lens element 130, a fourth lens element140, a fifth lens element 150, and a sixth lens element 160.

The first lens element 110 with positive refractive power has anobject-side surface 111 being convex in a paraxial region thereof, animage-side surface 112 being convex in a paraxial region thereof, boththe object-side surface 111 and the image-side surface 112 beingaspheric, and at least one inflection point on the object-side surface111. The first lens element 110 is made of plastic material.

The second lens element 120 with negative refractive power has anobject-side surface 121 being concave in a paraxial region thereof, animage-side surface 122 being convex in a paraxial region thereof, boththe object-side surface 121 and the image-side surface 122 beingaspheric, and at least one inflection point on each of the object-sidesurface 121 and the image-side surface 122. The second lens element 120is made of plastic material.

The third lens element 130 with negative refractive power has anobject-side surface 131 being convex in a paraxial region thereof, animage-side surface 132 being concave in a paraxial region thereof, andboth the object-side surface 131 and the image-side surface 132 beingaspheric. The third lens element 130 is made of plastic material.

The fourth lens element 140 with negative refractive power has anobject-side surface 141 being convex in a paraxial region thereof, animage-side surface 142 being concave in a paraxial region thereof, andboth the object-side surface 141 and the image-side surface 142 beingaspheric. The fourth lens element 140 is made of plastic material.

The fifth lens element 150 with negative refractive power has anobject-side surface 151 being concave in a paraxial region thereof, animage-side surface 152 being concave in a paraxial region thereof, boththe object-side surface 151 and the image-side surface 152 beingaspheric, and at least one inflection point on the image-side surface152. The fifth lens element 150 is made of plastic material.

The sixth lens element 160 with positive refractive power has anobject-side surface 161 being convex in a paraxial region thereof, animage-side surface 162 being concave in a paraxial region thereof, boththe object-side surface 161 and the image-side surface 162 beingaspheric, and at least one inflection point on each of the object-sidesurface 161 and the image-side surface 162. The sixth lens element 160is made of plastic material.

The optical imaging system further includes an IR cut filter 170 locatedbetween the sixth lens element 160 and an image surface 180. The IR cutfilter 170 is made of glass material and will not affect the focallength of the optical imaging system. The image sensor 190 is disposedon or near the image surface 180 of the optical imaging system.

The detailed optical data of the 1st embodiment are shown in TABLE 1,and the aspheric surface data are shown in TABLE 2, wherein the units ofthe curvature radius, the thickness and the focal length are expressedin mm, and HFOV is a half of the maximal field of view.

TABLE 1 (1st Embodiment) f = 5.82 mm, Fno = 1.45, HFOV = 23.7 deg.Curvature Focal Surface # Radius Thickness Material Index Abbe # Length0 Object Plano Infinity 1 Lens 1 2.245 ASP 1.800 Plastic 1.535 55.8 3.222 −5.337 ASP 0.132 3 Ape. Stop Plano 0.033 4 Lens 2 −3.289 ASP 0.217Plastic 1.671 19.5 −9.38 5 −7.072 ASP 0.032 6 Lens 3 7.610 ASP 0.428Plastic 1.535 55.8 −12.93 7 3.552 ASP 0.986 8 Lens 4 62.858 ASP 0.332Plastic 1.639 23.3 −34.72 9 16.358 ASP 0.096 10 Lens 5 −8.725 ASP 0.403Plastic 1.515 56.5 −9.20 11 10.513 ASP 0.050 12 Lens 6 5.132 ASP 1.000Plastic 1.639 23.3 41.36 13 5.885 ASP 0.300 14 IR Cut Filter Plano 0.210Glass 1.517 64.2 — 15 Plano 0.383 16 Image Plano — Surface Note:Reference wavelength is d-line 587.6 nm. The effective radius of Surface1 is 2.040 mm. The effective radius of Surface 10 is 1.450 mm.

TABLE 2 Aspheric Coefficients Surface # 1 2 4 5 k = −1.3122E+005.6214E+00 −1.0391E+01 1.9173E+01 A4 =  1.2002E−02 8.9744E−02 2.4400E−01 3.6588E−01 A6 = −1.7371E−03 −5.4131E−02  −2.0886E−01−2.2793E−01  A8 =  1.1928E−03 1.9192E−02  9.5009E−02 2.4860E−02 A10 =−2.8788E−04 −3.6228E−03  −2.0596E−02 3.7796E−02 A12 =  5.3670E−062.9533E−04  1.7734E−03 −9.2410E−03  Surface # 6 7 8 9 k = −3.5791E+01−2.2390E+01  −9.0000E+01 7.0391E+01 A4 =  1.9174E−01 4.6182E−02−1.3626E−01 −2.9257E−01  A6 = −5.7826E−02 1.8916E−02  1.0408E−013.1066E−01 A8 = −8.2370E−02 −4.7889E−02  −1.6734E−01 −3.3447E−01  A10 = 7.4505E−02 2.8109E−02  1.4673E−01 2.5471E−01 A12 = −1.5771E−02−6.6234E−03  −8.8781E−02 −1.1315E−01  A14 = −1.3313E−04  2.2879E−022.1227E−02 Surface # 10 11 12 13 k = −2.1724E−01 −1.3995E+01 −2.6841E+01 4.9107E+00 A4 = −1.9601E−01 −3.2794E−02  −5.2900E−02−5.2188E−02  A6 =  2.2850E−01 1.0855E−02 −2.2307E−02 3.7723E−03 A8 =−2.2493E−01 3.3426E−03  5.0558E−02 1.2067E−03 A10 =  1.7462E−01−6.4941E−03  −3.4376E−02 −8.2835E−04  A12 = −7.7830E−02 2.2008E−03 1.1692E−02 1.7078E−04 A14 =  1.3550E−02 −2.5089E−04  −1.9832E−03−1.1495E−05  A16 =  1.3293E−04 −2.0067E−07 

The equation of the aspheric surface profiles is expressed as follows:

${X(Y)} = {{( {Y^{2}/R} )/( {1 + {{sqrt}( {1 - {( {1 + k} )*( {Y/R} )^{2}}} )}} )} + {\sum\limits_{i}{({Ai})*( Y^{i} )}}}$

where:

X is the relative distance between a point on the aspheric surfacespaced at a distance Y from the optical axis and the tangential plane atthe aspheric surface vertex on the optical axis;

Y is the vertical distance from the point on the aspheric surfaceprofile to the optical axis;

R is the curvature radius;

k is the conic coefficient; and

Ai is the i-th aspheric coefficient.

In the 1st embodiment, a focal length of the optical imaging system isf, an f-number of the optical imaging system is Fno, a half of a maximalfield of view of the optical imaging system is HFOV, and theseparameters have the following values: f=5.82 mm; Fno=1.45; and HFOV=23.7degrees.

In the 1st embodiment, an Abbe number of the first lens element 110 isV1, an Abbe number of the second lens element 120 is V2, an Abbe numberof the third lens element 130 is V3, an Abbe number of the fourth lenselement 140 is V4, an Abbe number of the sixth lens element 160 is V6,and they satisfy the condition: (V2+V4+V6)/(V1+V3)=0.59.

In the 1st embodiment, the Abbe number of the first lens element 110 isV1, the Abbe number of the third lens element 130 is V3, the Abbe numberof the fourth lens element 140 is V4, an Abbe number of the fifth lenselement 150 is V5, the Abbe number of the sixth lens element 160 is V6,and they satisfy the condition: (V4+V5+V6)/(V1+V3)=0.92.

In the 1st embodiment, a central thickness of the first lens element 110is CT1, a central thickness of the second lens element 120 is CT2, acentral thickness of the third lens element 130 is CT3, a centralthickness of the fourth lens element 140 is CT4, a central thickness ofthe fifth lens element 150 is CT5, a central thickness of the sixth lenselement 160 is CT6, and they satisfy the condition:(CT2+CT3+CT4+CT5)/(CT1+CT6)=0.49.

In the 1st embodiment, a sum of axial distances between every twoadjacent lens elements of the optical imaging system is ΣAT, an axialdistance between the third lens element 130 and the fourth lens element140 is T34, and they satisfy the condition: ΣAT/T34=1.35.

In the 1st embodiment, a curvature radius of the image-side surface 132of the third lens element 130 is R6, a curvature radius of theobject-side surface 141 of the fourth lens element 140 is R7, and theysatisfy the condition: (R6+R7)/(R6−R7)=−1.12.

In the 1st embodiment, a curvature radius of the object-side surface 161of the sixth lens element 160 is R11, a curvature radius of theimage-side surface 162 of the sixth lens element 160 is R12, and theysatisfy the condition: (R11−R12)/(R11+R12)=−0.07.

In the 1st embodiment, a focal length of the first lens element 110 isf1, a focal length of the third lens element 130 is f3, and they satisfythe condition: |f1/f3|=0.25.

In the 1st embodiment, a curvature radius of the object-side surface 111of the first lens element 110 is R1, the central thickness of the firstlens element 110 is CT1, and they satisfy the condition: R1/CT1=1.25.

In the 1st embodiment, an axial distance between the image-side surface162 of the sixth lens element 160 and the image surface 180 is BL, thecentral thickness of the first lens element is CT1, and they satisfy thecondition: BL/CT1=0.50.

In the 1st embodiment, a half of the maximal field of view of theoptical imaging system is HFOV, and it satisfies the condition:tan(HFOV)=0.44.

In the 1st embodiment, an axial distance between the object-side surface111 of the first lens element 110 and the image surface 180 is TL, andit satisfies the condition: TL=6.40 mm.

In the 1st embodiment, the axial distance between the object-sidesurface 111 of the first lens element 110 and the image surface 180 isTL, an axial distance between the aperture stop 100 and the imagesurface 180 is SL, and they satisfy the condition: SL/TL=0.70.

In the 1st embodiment, the focal length of the optical imaging system isf, the axial distance between the object-side surface 111 of the firstlens element 110 and the image surface 180 is TL, and they satisfy thecondition: f/TL=0.91.

In the 1st embodiment, an entrance pupil diameter of the optical imagingsystem is EPD, a maximum image height of the optical imaging system isImgH, and they satisfy the condition: EPD/ImgH=1.53.

In the 1st embodiment, a vertical distance between a maximum effectivediameter position on the object-side surface 111 of the first lenselement 110 and an optical axis is Y11, the maximum image height of theoptical imaging system is ImgH, and they satisfy the condition:Y11/ImgH=0.78.

In the 1st embodiment, the vertical distance between a maximum effectivediameter position on the object-side surface 111 of the first lenselement 110 and the optical axis is Y11, a vertical distance between amaximum effective diameter position on the image-side surface 162 of thesixth lens element 160 and the optical axis is Y62,and they satisfy thecondition: Y11/Y62=0.94.

In the 1st embodiment, a vertical distance between an off-axial criticalpoint on the image-side surface 162 of the sixth lens element 160 andthe optical axis is Yc62, the focal length of the optical imaging systemis f, and they satisfy the condition: Yc62/f=0.17.

In the 1st embodiment, the axial distance between the object-sidesurface 111 of the first lens element 110 and the image surface 180 isTL, the entrance pupil diameter of the optical imaging system is EPD,and they satisfy the condition: TL/EPD=1.60.

In the 1st embodiment, the focal length of the optical imaging system isf, the entrance pupil diameter of the optical imaging system is EPD, andthey satisfy the condition: f/EPD=1.45.

2nd Embodiment

FIG. 2A is a schematic view of an imaging apparatus according to the 2ndembodiment of the present disclosure. FIG. 2B shows, in order from leftto right, longitudinal spherical aberration curves, astigmatic fieldcurves and a distortion curve of the imaging apparatus according to the2nd embodiment.

In FIG. 2A, the imaging apparatus includes an optical imaging system(not otherwise herein labeled) of the present disclosure and an imagesensor 290. The optical imaging system includes, in order from an objectside to an image side, a first lens element 210, an aperture stop 200, asecond lens element 220, a third lens element 230, a fourth lens element240, a fifth lens element 250, and a sixth lens element 260.

The first lens element 210 with positive refractive power has anobject-side surface 211 being convex in a paraxial region thereof, animage-side surface 212 being convex in a paraxial region thereof, boththe object-side surface 211 and the image-side surface 212 beingaspheric, and at least one inflection point on the object-side surface211. The first lens element 210 is made of plastic material.

The second lens element 220 with negative refractive power has anobject-side surface 221 being concave in a paraxial region thereof, animage-side surface 222 being convex in a paraxial region thereof, boththe object-side surface 221 and the image-side surface 222 beingaspheric, and at least one inflection point on each of the object-sidesurface 221 and the image-side surface 222. The second lens element 220is made of plastic material.

The third lens element 230 with negative refractive power has anobject-side surface 231 being convex in a paraxial region thereof, animage-side surface 232 being concave in a paraxial region thereof, andboth the object-side surface 231 and the image-side surface 232 beingaspheric. The third lens element 230 is made of plastic material.

The fourth lens element 240 with negative refractive power has anobject-side surface 241 being convex in a paraxial region thereof, animage-side surface 242 being concave in a paraxial region thereof, boththe object-side surface 241 and the image-side surface 242 beingaspheric, and at least one inflection point on the image-side surface242. The fourth lens element 240 is made of plastic material.

The fifth lens element 250 with negative refractive power has anobject-side surface 251 being concave in a paraxial region thereof, animage-side surface 252 being concave in a paraxial region thereof, boththe object-side surface 251 and the image-side surface 252 beingaspheric, and at least one inflection point on the image-side surface252. The fifth lens element 250 is made of plastic material.

The sixth lens element 260 with positive refractive power has anobject-side surface 261 being convex in a paraxial region thereof, animage-side surface 262 being concave in a paraxial region thereof, boththe object-side surface 261 and the image-side surface 262 beingaspheric, and at least one inflection point on each of the object-sidesurface 261 and the image-side surface 262. The sixth lens element 260is made of plastic material.

The optical imaging system further includes an IR cut filter 270 locatedbetween the sixth lens element 260 and an image surface 280. The IR cutfilter 270 is made of glass material and will not affect the focallength of the optical imaging system. The image sensor 290 is disposedon or near the image surface 280 of the optical imaging system.

The detailed optical data of the 2nd embodiment are shown in TABLE 3,and the aspheric surface data are shown in TABLE 4, wherein the units ofthe curvature radius, the thickness and the focal length are expressedin mm, and HFOV is a half of the maximal field of view.

TABLE 3 (2nd Embodiment) f = 5.75 mm, Fno = 1.50, HFOV = 24.0 deg.Curvature Focal Surface # Radius Thickness Material Index Abbe # Length0 Object Plano Infinity 1 Lens 1 2.071 ASP 1.759 Plastic 1.545 56.0 3.012 −5.479 ASP 0.117 3 Ape. Stop Plano 0.035 4 Lens 2 −2.708 ASP 0.175Plastic 1.671 19.5 −6.62 5 −7.118 ASP 0.051 6 Lens 3 4.159 ASP 0.342Plastic 1.535 55.8 −15.54 7 2.693 ASP 0.971 8 Lens 4 59.577 ASP 0.220Plastic 1.671 19.5 −43.63 9 19.596 ASP 0.080 10 Lens 5 −8.075 ASP 0.438Plastic 1.535 55.8 −8.39 11 10.282 ASP 0.090 12 Lens 6 5.078 ASP 0.771Plastic 1.671 19.5 44.36 13 5.750 ASP 0.300 14 IR Cut Filter Plano 0.210Glass 1.517 64.2 — 15 Plano 0.425 16 Image Plano — Surface Note:Reference wavelength is d-line 587.6 nm. The effective radius of Surface1 is 2.000 mm. The effective radius of Surface 5 is 1.365 mm. Theeffective radius of Surface 10 is 1.450 mm.

TABLE 4 Aspheric Coefficients Surface # 1 2 4 5 k = −1.1052E+006.2810E+00 −2.2955E+01 8.1165E−01 A4 =  1.3724E−02 8.7611E−02 2.3258E−01 3.6599E−01 A6 = −1.8086E−03 −5.2441E−02  −2.0858E−01−2.2855E−01  A8 =  1.1716E−03 1.9064E−02  9.7512E−02 2.4594E−02 A10 =−1.1601E−04 −3.7219E−03  −2.1130E−02 3.7500E−02 A12 = −3.4833E−053.1480E−04  1.8020E−03 −7.9553E−03  Surface # 6 7 8 9 k = −7.3611E+01−1.9149E+01   9.0000E+01 −9.0000E+01  A4 =  1.8303E−01 7.2903E−02−1.5262E−01 −2.9146E−01  A6 = −4.7103E−02 2.8313E−04  5.8495E−023.1012E−01 A8 = −8.6790E−02 −5.5405E−02  −1.3748E−01 −3.3466E−01  A10 = 7.3768E−02 3.9495E−02  1.4137E−01 2.5535E−01 A12 = −1.4003E−02−9.7164E−03  −9.8514E−02 −1.1269E−01  A14 = −4.0795E−04  1.9012E−022.1501E−02 A16 =  5.4173E−03 1.6089E−05 Surface # 10 11 12 13 k =−1.8930E+01 1.6677E+00 −1.5018E+01 4.9481E+00 A4 = −1.8761E−01−2.6878E−02  −8.0700E−02 −9.1967E−02  A6 =  2.3019E−01 −1.7264E−02 −2.2470E−03 2.9390E−02 A8 = −2.2415E−01 2.4479E−02  4.2119E−02−1.4276E−02  A10 =  1.7453E−01 −1.3402E−02  −2.7334E−02 7.0421E−03 A12 =−7.7923E−02 3.3993E−03  8.0320E−03 −2.1909E−03  A14 =  1.3478E−02−3.4839E−04  −1.1457E−03 3.4772E−04 A16 =  6.3286E−05 −2.1861E−05 

In the 2nd embodiment, the equation of the aspheric surface profiles ofthe aforementioned lens elements is the same as the equation of the 1stembodiment. Also, the definitions of these parameters shown in the tablebelow are the same as those stated in the 1st embodiment withcorresponding values for the 2nd embodiment, so an explanation in thisregard will not be provided again.

Moreover, these parameters can be calculated from TABLE 3 and TABLE 4and satisfy the conditions stated the table below.

2nd Embodiment f [mm] 5.75 BL/CT1 0.53 Fno. 1.50 tan(HFOV) 0.44 HFOV[deg.] 24.0 TL [mm] 5.98 (V2 + V4 + V6)/(V1 + V3) 0.52 SL/TL 0.69 (V4 +V5 + V6)/(V1 + V3) 0.85 f/TL 0.96 (CT2 + CT3 + CT4 + CT5)/(CT1 + CT6)0.46 EPD/ImgH 1.46 Σ AT/T34 1.38 Y11/ImgH 0.76 (R6 + R7)/(R6 − R7) −1.09Y11/Y62 0.95 (R11 − R12)/(R11 + R12) −0.06 Yc62/f 0.14 |f1/f3| 0.19TL/EPD 1.56 R1/CT1 1.18 f/EPD 1.50

3rd Embodiment

FIG. 3A is a schematic view of an imaging apparatus according to the 3rdembodiment of the present disclosure. FIG. 3B shows, in order from leftto right, longitudinal spherical aberration curves, astigmatic fieldcurves and a distortion curve of the imaging apparatus according to the3rd embodiment.

In FIG. 3A, the imaging apparatus includes an optical imaging system(not otherwise herein labeled) of the present disclosure and an imagesensor 390. The optical imaging system includes, in order from an objectside to an image side, an aperture stop 300, a first lens element 310, asecond lens element 320, a third lens element 330, a fourth lens element340, a fifth lens element 350, and a sixth lens element 360.

The first lens element 310 with positive refractive power has anobject-side surface 311 being convex in a paraxial region thereof, animage-side surface 312 being convex in a paraxial region thereof, andboth the object-side surface 311 and the image-side surface 312 beingaspheric. The first lens element 310 is made of plastic material.

The second lens element 320 with negative refractive power has anobject-side surface 321 being concave in a paraxial region thereof, animage-side surface 322 being convex in a paraxial region thereof, boththe object-side surface 321 and the image-side surface 322 beingaspheric, and at least one inflection point on each of the object-sidesurface 321 and the image-side surface 322. The second lens element 320is made of plastic material.

The third lens element 330 with negative refractive power has anobject-side surface 331 being convex in a paraxial region thereof, animage-side surface 332 being concave in a paraxial region thereof, andboth the object-side surface 331 and the image-side surface 332 beingaspheric. The third lens element 330 is made of plastic material.

The fourth lens element 340 with positive refractive power has anobject-side surface 341 being convex in a paraxial region thereof, animage-side surface 342 being convex in a paraxial region thereof, boththe object-side surface 341 and the image-side surface 342 beingaspheric, and at least one inflection point on the object-side surface341. The fourth lens element 340 is made of plastic material.

The fifth lens element 350 with negative refractive power has anobject-side surface 351 being concave in a paraxial region thereof, animage-side surface 352 being concave in a paraxial region thereof, boththe object-side surface 351 and the image-side surface 352 beingaspheric, and at least one inflection point on the image-side surface352. The fifth lens element 350 is made of plastic material.

The sixth lens element 360 with positive refractive power has anobject-side surface 361 being convex in a paraxial region thereof, animage-side surface 362 being concave in a paraxial region thereof, boththe object-side surface 361 and the image-side surface 362 beingaspheric, and at least one inflection point on each of the object-sidesurface 361 and the image-side surface 362. The sixth lens element 360is made of plastic material.

The optical imaging system further includes an IR cut filter 370 locatedbetween the sixth lens element 360 and an image surface 380. The IR cutfilter 370 is made of glass material and will not affect the focallength of the optical imaging system. The image sensor 390 is disposedon or near the image surface 380 of the optical imaging system.

The detailed optical data of the 3rd embodiment are shown in TABLE 5,and the aspheric surface data are shown in TABLE 6, wherein the units ofthe curvature radius, the thickness and the focal length are expressedin mm, and HFOV is a half of the maximal field of view.

TABLE 5 (3rd Embodiment) f = 5.88 mm, Fno = 1.45, HFOV = 23.4 deg.Curvature Focal Surface # Radius Thickness Material Index Abbe # Length0 Object Plano Infinity 1 Ape. Stop Plano −0.914 2 Lens 1 2.335 ASP1.800 Plastic 1.535 55.8 3.31 3 −5.354 ASP 0.152 4 Lens 2 −4.969 ASP0.215 Plastic 1.660 20.4 −8.17 5 −64.883 ASP 0.043 6 Lens 3 5.220 ASP0.447 Plastic 1.535 55.8 −18.06 7 3.288 ASP 0.988 8 Lens 4 66.483 ASP0.432 Plastic 1.639 23.3 16.00 9 −12.045 ASP 0.052 10 Lens 5 −3.839 ASP0.385 Plastic 1.583 30.2 −3.91 11 5.834 ASP 0.050 12 Lens 6 3.705 ASP1.192 Plastic 1.639 23.3 12.57 13 6.017 ASP 0.300 14 IR Cut Filter Plano0.210 Glass 1.517 64.2 — 15 Plano 0.344 16 Image Plano — Surface Note:Reference wavelength is d-line 587.6 nm. The effective radius of Surface10 is 1.450 mm.

TABLE 6 Aspheric Coefficients Surface # 2 3 4 5 k = −1.4452E+005.6197E+00 −7.5061E+00 −9.0000E+01  A4 =  1.1335E−02 8.6447E−02 2.4004E−01 3.3215E−01 A6 = −1.4322E−03 −5.3809E−02  −2.1133E−01−2.3580E−01  A8 =  9.9625E−04 1.9506E−02  9.5299E−02 2.5034E−02 A10 =−2.9175E−04 −3.6800E−03  −2.0244E−02 3.9827E−02 A12 =  1.6448E−052.9839E−04  1.6744E−03 −1.0574E−02  Surface # 6 7 9 8 k = −1.9362E+01−1.6745E+01  −2.7680E+01 9.0000E+01 A4 =  1.8410E−01 3.2899E−02−2.8885E−01 −1.1171E−01  A6 = −6.2406E−02 1.9470E−02  3.1151E−018.6364E−02 A8 = −8.2844E−02 −4.6619E−02  −3.3464E−01 −1.7775E−01  A10 = 7.5382E−02 2.8216E−02  2.5473E−01 1.5137E−01 A12 = −1.6042E−02−6.5063E−03  −1.1320E−01 −8.3122E−02  A14 =  2.1226E−02 2.0303E−02Surface # 10 11 12 13 k = −8.6024E+00 1.7933E−01 −3.4171E+01 4.9397E+00A4 = −1.9301E−01 −4.6258E−02  −4.7344E−02 −4.9004E−02  A6 =  2.2762E−011.1896E−02 −2.2229E−02 3.9769E−03 A8 = −2.2493E−01 3.5337E−03 5.0593E−02 1.1691E−03 A10 =  1.7446E−01 −6.4796E−03  −3.4368E−02−8.2575E−04  A12 = −7.7870E−02 2.2069E−03  1.1691E−02 1.7145E−04 A14 = 1.3516E−02 −2.4893E−04  −1.9836E−03 −1.1313E−05  A16 =  1.3283E−04−1.8092E−07 

In the 3rd embodiment, the equation of the aspheric surface profiles ofthe aforementioned lens elements is the same as the equation of the 1stembodiment. Also, the definitions of these parameters shown in the tablebelow are the same as those stated in the 1st embodiment withcorresponding values for the 3rd embodiment, so an explanation in thisregard will not be provided again.

Moreover, these parameters can be calculated from TABLE 5 and TABLE 6and satisfy the conditions stated in table below

3rd Embodiment f [mm] 5.88 BL/CT1 0.47 Fno. 1.45 tan(HFOV) 0.43 HFOV[deg.] 23.4 TL [mm] 6.61 (V2 + V4 + V6)/(V1 + V3) 0.60 SL/TL 0.86 (V4 +V5 + V6)/(V1 + V3) 0.69 f/TL 0.89 (CT2 + CT3 + CT4 + CT5)/(CT1 + CT6)0.49 EPD/ImgH 1.55 ΣAT/T34 1.30 Y11/ImgH 0.77 (R6 + R7)/(R6 − R7) −1.10Y11/Y62 0.87 (R11 − R12)/(R11 + R12) −0.24 Yc62/f 0.18 |f1/f3| 0.18TL/EPD 1.63 R1/CT1 1.30 f/EPD 1.45

4th Embodiment

FIG. 4A is a schematic view of an imaging apparatus according to the 4thembodiment of the present disclosure. FIG. 4B shows, in order from leftto right, longitudinal spherical aberration curves, astigmatic fieldcurves and a distortion curve of the imaging apparatus according to the4th embodiment.

In FIG. 4A, the imaging apparatus includes an optical imaging system(not otherwise herein labeled) of the present disclosure and an imagesensor 490. The optical imaging system includes, in order from an objectside to an image side, a first lens element 410, an aperture stop 400, asecond lens element 420, a third lens element 430, a fourth lens element440, a fifth lens element 450, and a sixth lens element 460.

The first lens element 410 with positive refractive power has anobject-side surface 411 being convex in a paraxial region thereof, animage-side surface 412 being concave in a paraxial region thereof, boththe object-side surface 411 and the image-side surface 412 beingaspheric, and at least one inflection on the image-side surface 412. Thefirst lens element 410 is made of plastic material.

The second lens element 420 with negative refractive power has anobject-side surface 421 being convex in a paraxial region thereof, animage-side surface 422 being concave in a paraxial region thereof, andboth the object-side surface 421 and the image-side surface 422 beingaspheric. The second lens element 420 is made of plastic material.

The third lens element 430 with positive refractive power has anobject-side surface 431 being convex in a paraxial region thereof, animage-side surface 432 being concave in a paraxial region thereof, boththe object-side surface 431 and the image-side surface 432 beingaspheric, and at least one inflection point on the image-side surface432. The third lens element 430 is made of plastic material.

The fourth lens element 440 with positive refractive power has anobject-side surface 441 being concave in a paraxial region thereof, animage-side surface 442 being convex in a paraxial region thereof, andboth the object-side surface 441 and the image-side surface 442 beingaspheric. The fourth lens element 440 is made of plastic material.

The fifth lens element 450 with negative refractive power has anobject-side surface 451 being concave in a paraxial region thereof, animage-side surface 452 being concave in a paraxial region thereof, boththe object-side surface 451 and the image-side surface 452 beingaspheric, ant at least one inflection point on the image-side surface452. The fifth lens element 450 is made of plastic material.

The sixth lens element 460 with negative refractive power has anobject-side surface 461 being convex in a paraxial region thereof, animage-side surface 462 being concave in a paraxial region thereof, boththe object-side surface 461 and the image-side surface 462 beingaspheric, and at least one inflection point on each of the object-sidesurface 461 and the image-side surface 462. The sixth lens element 460is made of plastic material.

The optical imaging system further includes an IR cut filter 470 locatedbetween the sixth lens element 460 and an image surface 480. The IR cutfilter 470 is made of glass material and will not affect the focallength of the optical imaging system. The image sensor 490 is disposedon or near the image surface 480 of the optical imaging system.

The detailed optical data of the 4th embodiment are shown in TABLE 7,and the aspheric surface data are shown in TABLE 8, wherein the units ofthe curvature radius, the thickness and the focal length are expressedin mm, and HFOV is a half of the maximal field of view.

TABLE 7 (4th Embodiment) f = 5.68 mm, Fno = 1.35, HFOV = 23.8 deg.Curvature Focal Surface # Radius Thickness Material Index Abbe # Length0 Object Plano Infinity 1 Lens 1 2.351 ASP 1.800 Plastic 1.535 55.8 4.622 35.282 ASP 0.140 3 Ape. Stop Plano 0.030 4 Lens 2 46.729 ASP 0.201Plastic 1.671 19.5 −7.05 5 4.288 ASP 0.038 6 Lens 3 2.300 ASP 0.596Plastic 1.535 55.8 9.36 7 3.870 ASP 0.913 8 Lens 4 −56.464 ASP 0.435Plastic 1.639 23.3 7.24 9 −4.286 ASP 0.059 10 Lens 5 −2.493 ASP 0.382Plastic 1.583 30.2 −4.08 11 56.685 ASP 0.068 12 Lens 6 8.312 ASP 1.200Plastic 1.671 19.5 −51.08 13 6.302 ASP 0.300 14 IR Cut Filter Plano0.210 Glass 1.517 64.2 — 15 Plano 0.319 16 Image Plano — Surface Note:Reference wavelength is d-line 587.6 nm. The effective radius of Surface10 is 1.470 mm.

TABLE 8 Aspheric Coefficients Surface # 1 2 4 5 k = −1.5666E+00−9.0000E+01   4.9328E+01 −3.8840E+01 A4 =  1.1781E−02 5.7135E−02 2.2805E−01  3.2012E−01 A6 = −7.0440E−04 −5.4412E−02  −2.1981E−01−2.3656E−01 A8 =  6.1980E−04 2.0254E−02  9.6342E−02  2.3409E−02 A10 =−2.0817E−04 −3.5311E−03  −1.8724E−02  3.9435E−02 A12 =  1.6088E−052.4013E−04  1.3247E−03 −1.0196E−02 Surface # 6 7 8 9 k = −1.5353E+01−2.4132E+01  −9.0000E+01 −4.2868E+01 A4 =  1.8326E−01 1.8248E−02−9.8262E−02 −2.8210E−01 A6 = −6.3462E−02 2.0668E−02  8.0799E−02 3.1120E−01 A8 = −8.3611E−02 −4.4918E−02  −1.7495E−01 −3.3162E−01 A10 = 7.3259E−02 2.7460E−02  1.5258E−01  2.5187E−01 A12 = −1.5091E−02−6.3058E−03  −8.3638E−02 −1.1358E−01 A14 =  1.9593E−02  2.1274E−02Surface # 10 11 12 13 k = −2.5547E+00 9.0000E+01 −9.0000E+01  5.0209E+00A4 = −1.6210E−01 −2.2748E−02  −4.5448E−02 −3.5277E−02 A6 =  2.2536E−013.7134E−03 −2.0795E−02 −1.0048E−03 A8 = −2.2682E−01 4.3273E−03 4.9507E−02  3.3662E−03 A10 =  1.7312E−01 −6.3985E−03  −3.4248E−02−1.3496E−03 A12 = −7.7817E−02 2.1526E−03  1.1691E−02  2.4948E−04 A14 = 1.3705E−02 −2.3597E−04  −1.9831E−03 −2.1771E−05 A16 =  1.3288E−04 6.3308E−07

In the 4th embodiment, the equation of the aspheric surface profiles ofthe aforementioned lens elements is the same as the equation of the 1stembodiment. Also, the definitions of these parameters shown in the tablebelow are the same as those stated in the 1st embodiment withcorresponding values for the 4th embodiment, so an explanation in thisregard will not be provided again.

Moreover, these parameters can be calculated from TABLE 7 and TABLE 8and satisfy the conditions stated in the table below.

4th Embodiment f [mm] 5.68 BL/CT1 0.46 Fno. 1.35 tan(HFOV) 0.44 HFOV[deg.] 23.8 TL [mm] 6.69 (V2 + V4 + V6)/(V1 + V3) 0.56 SL/TL 0.71 (V4 +V5 + V6)/(V1 + V3) 0.65 f/TL 0.85 (CT2 + CT3 + CT4 + CT5)/(CT1 + CT6)0.54 EPD/ImgH 1.61 Σ AT/T34 1.37 Y11/ImgH 0.88 (R6 + R7)/(R6 − R7) −0.87Y11/Y62 1.07 (R11 − R12)/(R11 + R12) 0.14 Yc62/f 0.21 |f1/f3| 0.49TL/EPD 1.59 R1/CT1 1.31 f/EPD 1.35

5th Embodiment

FIG. 5A is a schematic view of an imaging apparatus according to the 5thembodiment of the present disclosure. FIG. 5B shows, in order from leftto right, longitudinal spherical aberration curves, astigmatic fieldcurves and a distortion curve of the imaging apparatus according to the5th embodiment.

In FIG. 5A, the imaging apparatus includes an optical imaging system(not otherwise herein labeled) of the present disclosure and an imagesensor 590. The optical imaging system includes, in order from an objectside to an image side, a first lens element 510, an aperture stop 500, asecond lens element 520, a third lens element 530, a fourth lens element540, a fifth lens element 550, and a sixth lens element 560.

The first lens element 510 with positive refractive power has anobject-side surface 511 being convex in a paraxial region thereof, animage-side surface 512 being concave in a paraxial region thereof, andboth the object-side surface 511 and the image-side surface 512 beingaspheric. The first lens element 510 is made of plastic material.

The second lens element 520 with negative refractive power has anobject-side surface 521 being convex in a paraxial region thereof, animage-side surface 522 being concave in a paraxial region thereof, andboth the object-side surface 521 and the image-side surface 522 beingaspheric. The second lens element 520 is made of plastic material.

The third lens element 530 with positive refractive power has anobject-side surface 531 being convex in a paraxial region thereof, animage-side surface 532 being concave in a paraxial region thereof, andboth the object-side surface 531 and the image-side surface 532 beingaspheric. The third lens element 530 is made of plastic material.

The fourth lens element 540 with positive refractive power has anobject-side surface 541 being convex in a paraxial region thereof, animage-side surface 542 being convex in a paraxial region thereof, boththe object-side surface 541 and the image-side surface 542 beingaspheric, and at least one inflection point on the object-side surface541. The fourth lens element 540 is made of plastic material.

The fifth lens element 550 with negative refractive power has anobject-side surface 551 being concave in a paraxial region thereof, animage-side surface 552 being convex in a paraxial region thereof, andboth the object-side surface 551 and the image-side surface 552 beingaspheric The fifth lens element 550 is made of plastic material.

The sixth lens element 560 with negative refractive power has anobject-side surface 561 being concave in a paraxial region thereof, animage-side surface 562 being convex in a paraxial region thereof, boththe object-side surface 561 and the image-side surface 562 beingaspheric, and at least one inflection point on the image-side surface562. The sixth lens element 560 is made of plastic material.

The optical imaging system further includes an IR cut filter 570 locatedbetween the sixth lens element 560 and an image surface 580. The IR cutfilter 570 is made of glass material and will not affect the focallength of the optical imaging system. The image sensor 590 is disposedon or near the image surface 580 of the optical imaging system.

The detailed optical data of the 5th embodiment are shown in TABLE 9,and the aspheric surface data are shown in TABLE 10, wherein the unitsof the curvature radius, the thickness and the focal length areexpressed in mm, and HFOV is a half of the maximal field of view.

TABLE 9 (5th Embodiment) f = 5.65 mm, Fno = 1.35, HFOV = 23.8 deg.Curvature Focal Surface # Radius Thickness Material Index Abbe # Length0 Object Plano Infinity 1 Lens 1 2.377 ASP 1.800 Plastic 1.535 55.8 4.732 28.626 ASP 0.177 3 Ape. Stop Plano 0.030 4 Lens 2 41.858 ASP 0.224Plastic 1.671 19.5 −7.09 5 4.264 ASP 0.035 6 Lens 3 2.237 ASP 0.644Plastic 1.535 55.8 8.65 7 3.896 ASP 0.898 8 Lens 4 36.304 ASP 0.526Plastic 1.639 23.3 4.36 9 −3.001 ASP 0.062 10 Lens 5 −2.049 ASP 0.511Plastic 1.583 30.2 −4.86 11 −8.068 ASP 0.114 12 Lens 6 −4.222 ASP 1.200Plastic 1.671 19.5 −6.99 13 −47.393 ASP 0.200 14 IR Cut Filter Plano0.210 Glass 1.517 64.2 — 15 Plano 0.141 16 Image Plano — Surface Note:Reference wavelength is d-line 587.6 nm. The effective radius of Surface1 is 2.040 mm. The effective radius of Surface 10 is 1.480 mm.

TABLE 10 Aspheric Coefficients Surface # 1 2 4 5 k = −1.5850E+00−7.3740E+01 8.3184E+01 −4.2379E+01 A4 =  1.1716E−02  5.6895E−022.2810E−01  3.1929E−01 A6 = −7.1348E−04 −5.3784E−02 −2.2103E−01 −2.3767E−01 A8 =  5.9164E−04  2.0030E−02 9.5793E−02  2.2638E−02 A10 =−2.0114E−04 −3.5383E−03 −1.8658E−02   3.9283E−02 A12 =  1.7417E−05 2.5297E−04 1.3678E−03 −1.0098E−02 Surface # 6 7 8 9 k = −1.6674E+01−2.9760E+01 9.0000E+01 −3.4846E+01 A4 =  1.8067E−01  1.1653E−02−9.5138E−02  −2.8633E−01 A6 = −6.3121E−02  2.0970E−02 6.9922E−02 3.0931E−01 A8 = −8.3196E−02 −4.4024E−02 −1.7684E−01  −3.3203E−01 A10 = 7.3251E−02  2.7872E−02 1.5184E−01  2.5185E−01 A12 = −1.5041E−02−6.4336E−03 −8.3536E−02  −1.1356E−01 A14 = 2.0125E−02  2.1278E−02Surface # 10 11 12 13 k = −2.6705E+00 −9.0000E+01 −5.1597E+01 −9.0000E+01 A4 = −1.5988E−01 −4.9285E−03 −3.6395E−02   2.3917E−02 A6 = 2.2633E−01  4.5999E−04 −2.0507E−02  −3.4310E−02 A8 = −2.2692E−01 4.2778E−03 4.9511E−02  1.7811E−02 A10 =  1.7295E−01 −6.3621E−03−3.4252E−02  −5.5074E−03 A12 = −7.7909E−02  2.1422E−03 1.1690E−02 1.0110E−03 A14 =  1.3664E−02 −2.3631E−04 −1.9838E−03  −9.9728E−05 A16 =1.3266E−04  4.0119E−06

In the 5th embodiment, the equation of the aspheric surface profiles ofthe aforementioned lens elements is the same as the equation of the 1stembodiment. Also, the definitions of these parameters shown in the tablebelow are the same as those stated in the 1st embodiment withcorresponding values for the 5th embodiment, so an explanation in thisregard will not be provided again.

Moreover, these parameters can be calculated from TABLE 9 and TABLE 10and satisfy the conditions stated in the table below.

5th Embodiment f [mm] 5.65 BL/CT1 0.31 Fno. 1.35 tan(HFOV) 0.44 HFOV[deg.] 23.8 TL [mm] 6.77 (V2 + V4 + V6)/(V1 + V3) 0.56 SL/TL 0.71 (V4 +V5 + V6)/(V1 + V3) 0.65 f/TL 0.83 (CT2 + CT3 + CT4 + CT5)/(CT1 + CT6)0.64 EPD/ImgH 1.60 Σ AT/T34 1.47 Y11/ImgH 0.78 (R6 + R7)/(R6 − R7) −1.24Y11/Y62 0.91 (R11 − R12)/(R11 + R12) −0.84 Yc62/f — |f1/f3| 0.55 TL/EPD1.62 R1/CT1 1.32 f/EPD 1.35

6th Embodiment

FIG. 6A is a schematic view of an imaging apparatus according to the 6thembodiment of the present disclosure. FIG. 6B shows, in order from leftto right, longitudinal spherical aberration curves, astigmatic fieldcurves and a distortion curve of the imaging apparatus according to the6th embodiment.

In FIG. 6A, the imaging apparatus includes an optical imaging system(not otherwise herein labeled) of the present disclosure and an imagesensor 690. The optical imaging system includes, in order from an objectside to an image side, an aperture stop 600, a first lens element 610, asecond lens element 620, a third lens element 630, a fourth lens element640, a fifth lens element 650, and a sixth lens element 660.

The first lens element 610 with positive refractive power has anobject-side surface 611 being convex in a paraxial region thereof, animage-side surface 612 being convex in a paraxial region thereof, boththe object-side surface 611 and the image-side surface 612 beingaspheric, and at least one inflection point on the image-side surface612. The first lens element 610 is made of plastic material.

The second lens element 620 with negative refractive power has anobject-side surface 621 being concave in a paraxial region thereof, animage-side surface 622 being concave in a paraxial region thereof, boththe object-side surface 621 and the image-side surface 622 beingaspheric, and at least one inflection point on the object-side surface621. The second lens element 620 is made of plastic material.

The third lens element 630 with negative refractive power has anobject-side surface 631 being convex in a paraxial region thereof, animage-side surface 632 being concave in a paraxial region thereof, andboth the object-side surface 631 and the image-side surface 632 beingaspheric. The third lens element 630 is made of plastic material.

The fourth lens element 640 with positive refractive power has anobject-side surface 641 being convex in a paraxial region thereof, animage-side surface 642 being convex in a paraxial region thereof, boththe object-side surface 641 and the image-side surface 642 beingaspheric, and at least one inflection point on the object-side surface641. The fourth lens element 640 is made of plastic material.

The fifth lens element 650 with negative refractive power has anobject-side surface 651 being concave in a paraxial region thereof, animage-side surface 652 being concave in a paraxial region thereof, boththe object-side surface 651 and the image-side surface 652 beingaspheric, and at least one inflection point on each of the object-sidesurface 651 and the image-side surface 652. The fifth lens element 650is made of plastic material.

The sixth lens element 660 with positive refractive power has anobject-side surface 661 being convex in a paraxial region thereof, animage-side surface 662 being concave in a paraxial region thereof, boththe object-side surface 661 and the image-side surface 662 beingaspheric, and at least one inflection point on each of the object-sidesurface 661 and the image-side surface 662. The sixth lens element 660is made of plastic material.

The optical imaging system further includes an IR cut filter 670 locatedbetween the sixth lens element 660 and an image surface 680. The IR cutfilter 670 is made of glass material and will not affect the focallength of the optical imaging system. The image sensor 690 is disposedon or near the image surface 680 of the optical imaging system.

The detailed optical data of the 6th embodiment are shown in TABLE 15,and the aspheric surface data are shown in TABLE 16, wherein the unitsof the curvature radius, the thickness and the focal length areexpressed in mm, and HFOV is a half of the maximal field of view.

TABLE 11 (6th Embodiment) f = 6.23 mm, Fno = 1.50, HFOV = 22.0 deg.Curvature Focal Surface # Radius Thickness Material Index Abbe # Length0 Object Plano Infinity 1 Ape. Stop Plano −1.224 2 Lens 1 2.229 ASP1.793 Plastic 1.535 55.8 3.33 3 −6.400 ASP 0.147 4 Lens 2 −6.988 ASP0.207 Plastic 1.671 19.5 −7.65 5 19.518 ASP 0.069 6 Lens 3 4.040 ASP0.367 Plastic 1.535 55.8 −15.26 7 2.617 ASP 1.114 8 Lens 4 69.131 ASP0.342 Plastic 1.639 23.3 10.71 9 −7.579 ASP 0.054 10 Lens 5 −3.227 ASP0.390 Plastic 1.583 30.2 −4.29 11 11.687 ASP 0.118 12 Lens 6 5.446 ASP1.200 Plastic 1.671 19.5 43.69 13 6.097 ASP 0.300 14 IR Cut Filter Plano0.210 Glass 1.517 64.2 — 15 Plano 0.377 16 Image Plano — Surface Note:Reference wavelength is d-line 587.6 nm.

TABLE 12 Aspheric Coefficients Surface # 2 3 4 5 k = −1.3053E+007.9134E+00 −1.4106E+01 −8.9083E+01 A4 =  1.2770E−02 9.1050E−02 2.4043E−01  3.2920E−01 A6 = −5.7648E−04 −5.3880E−02  −2.1405E−01−2.3717E−01 A8 =  9.4460E−04 1.9526E−02  9.4325E−02  2.3963E−02 A10 =−2.2821E−04 −3.6552E−03  −1.9901E−02  3.9284E−02 A12 =  2.2541E−052.8968E−04  1.6205E−03 −1.0735E−02 Surface # 6 7 8 9 k = −1.0436E+01−5.5542E+00  −6.5419E+01 −4.9065E+01 A4 =  1.8516E−01 3.1173E−02−1.1240E−01 −2.7593E−01 A6 = −6.2838E−02 1.9963E−02  9.5560E−02 3.0789E−01 A8 = −8.4047E−02 −4.4309E−02  −1.8283E−01 −3.3762E−01 A10 = 7.4392E−02 2.8210E−02  1.4970E−01  2.5483E−01 A12 = −1.5875E−02−6.3710E−03  −8.1020E−02 −1.1347E−01 A14 =  1.8809E−02  2.1091E−02Surface # 10 11 12 13 k = −1.0831E+01 −2.1517E+01  −8.2720E+01 4.9021E+00 A4 = −1.9605E−01 −4.7704E−02  −4.2763E−02 −6.5073E−02 A6 = 2.2870E−01 1.0398E−02 −3.8864E−02  1.5401E−02 A8 = −2.2427E−013.4695E−03  6.5118E−02 −4.5988E−03 A10 =  1.7435E−01 −6.4990E−03 −4.0835E−02  1.2162E−03 A12 = −7.7658E−02 2.2119E−03  1.3226E−02−2.3055E−04 A14 =  1.3268E−02 −2.4512E−04  −2.1648E−03  2.6594E−05 A16 = 1.4088E−04 −1.4608E−06

In the 6th embodiment, the equation of the aspheric surface profiles ofthe aforementioned lens elements is the same as the equation of the 1stembodiment. Also, the definitions of these parameters shown in the tablebelow are the same as those stated in the 1st embodiment withcorresponding values for the 6th embodiment, so an explanation in thisregard will not be provided again.

Moreover, these parameters can be calculated from TABLE 11 and TABLE 12and satisfy the conditions stated in the table below.

6th Embodiment f [mm] 6.23 BL/CT1 0.49 Fno. 1.50 tan(HFOV) 0.40 HFOV[deg.] 22.0 TL [mm] 6.69 (V2 + V4 + V6)/(V1 + V3) 0.56 SL/TL 0.82 (V4 +V5 + V6)/(V1 + V3) 0.65 f/TL 0.93 (CT2 + CT3 + CT4 + CT5)/(CT1 + CT6)0.44 EPD/ImgH 1.60 Σ AT/T34 1.35 Y11/ImgH 0.80 (R6 + R7)/(R6 − R7) −1.08Y11/Y62 0.89 (R11 − R12)/(R11 + R12) −0.06 Yc62/f 0.15 |f1/f3| 0.22TL/EPD 1.61 R1/CT1 1.24 f/EPD 1.50

7th Embodiment

FIG. 7A is a schematic view of an imaging apparatus according to the 7thembodiment of the present disclosure. FIG. 7B shows, in order from leftto right, longitudinal spherical aberration curves, astigmatic fieldcurves and a distortion curve of the imaging apparatus according to the7th embodiment.

In FIG. 7A, the imaging apparatus includes an optical imaging system(not otherwise herein labeled) of the present disclosure and an imagesensor 790. The optical imaging system includes, in order from an objectside to an image side, a first lens element 710, an aperture stop 700, asecond lens element 720, a third lens element 730, a fourth lens element740, a fifth lens element 750, and a sixth lens element 760.

The first lens element 710 with positive refractive power has anobject-side surface 711 being convex in a paraxial region thereof, animage-side surface 712 being convex in a paraxial region thereof, boththe object-side surface 711 and the image-side surface 712 beingaspheric, and at least one inflection point on the object-side surface711. The first lens element 710 is made of plastic material.

The second lens element 720 with negative refractive power has anobject-side surface 721 being concave in a paraxial region thereof, animage-side surface 722 being convex in a paraxial region thereof, boththe object-side surface 721 and the image-side surface 722 beingaspheric, and at least one inflection point on each of the object-sidesurface 721 and the image-side surface 722. The second lens element 720is made of plastic material.

The third lens element 730 with negative refractive power has anobject-side surface 731 being convex in a paraxial region thereof, animage-side surface 732 being concave in a paraxial region thereof, andboth the object-side surface 731 and the image-side surface 732 beingaspheric. The third lens element 730 is made of plastic material.

The fourth lens element 740 with positive refractive power has anobject-side surface 741 being convex in a paraxial region thereof, animage-side surface 742 being convex in a paraxial region thereof, boththe object-side surface 741 and the image-side surface 742 beingaspheric, and at least one inflection point on the object-side surface741. The fourth lens element 740 is made of plastic material.

The fifth lens element 750 with negative refractive power has anobject-side surface 751 being concave in a paraxial region thereof, animage-side surface 752 being concave in a paraxial region thereof, boththe object-side surface 751 and the image-side surface 752 beingaspheric, and at least one inflection point on the image-side surface752. The fifth lens element 750 is made of plastic material.

The sixth lens element 760 with positive refractive power has anobject-side surface 761 being convex in a paraxial region thereof, animage-side surface 762 being concave in a paraxial region thereof, boththe object-side surface 761 and the image-side surface 762 beingaspheric, and at least one inflection point on each of the object-sidesurface 761 and the image-side surface 762. The sixth lens element 760is made of plastic material.

The optical imaging system further includes an IR cut filter 770 locatedbetween the sixth lens element 760 and an image surface 780. The IR cutfilter 770 is made of glass material and will not affect the focallength of the optical imaging system. The image sensor 790 is disposedon or near the image surface 780 of the optical imaging system.

The detailed optical data of the 7th embodiment are shown in TABLE 13,and the aspheric surface data are shown in TABLE 14, wherein the unitsof the curvature radius, the thickness and the focal length areexpressed in mm, and HFOV is a half of the maximal field of view.

TABLE 13 (7th Embodiment) f = 5.87 mm, Fno = 1.45, HFOV = 23.4 deg.Curvature Focal Surface # Radius Thickness Material Index Abbe # Length0 Object Plano Infinity 1 Lens 1 2.298 ASP 1.800 Plastic 1.535 55.8 3.222 −4.989 ASP 0.135 3 Ape. Stop Plano 0.035 4 Lens 2 −3.190 ASP 0.239Plastic 1.660 20.4 −9.24 5 −6.892 ASP 0.033 6 Lens 3 8.213 ASP 0.418Plastic 1.535 55.8 −13.13 7 3.719 ASP 0.950 8 Lens 4 71.522 ASP 0.428Plastic 1.639 23.3 19.42 9 −14.975 ASP 0.052 10 Lens 5 −4.094 ASP 0.386Plastic 1.583 30.2 −4.20 11 6.333 ASP 0.050 12 Lens 6 3.871 ASP 1.175Plastic 1.639 23.3 13.53 13 6.180 ASP 0.300 14 IR Cut Filter Plano 0.210Glass 1.517 64.2 — 15 Plano 0.400 16 Image Plano — Surface Note:Reference wavelength is d-line 587.6 nm. The effective radius of Surface1 is 2.040 mm. The effective radius of Surface 10 is 1.450 mm.

TABLE 14 Aspheric Coefficients Surface # 1 2 4 5 k = −1.4348E+004.5883E+00 −8.4535E+00 1.8586E+01 A4 =  1.1686E−02 9.0062E−02 2.4532E−01 3.6569E−01 A6 = −1.3727E−03 −5.4982E−02  −2.0935E−01−2.3257E−01  A8 =  9.4671E−04 1.9638E−02  9.4525E−02 2.4508E−02 A10 =−2.8743E−04 −3.6635E−03  −2.0241E−02 3.8432E−02 A12 =  1.2894E−052.9011E−04  1.6875E−03 −9.6868E−03  A14 = Surface # 6 7 8 9 k =−7.3764E+01 −2.5767E+01  −9.0000E+01 −9.0000E+01  A4 =  1.9073E−013.5774E−02 −1.0849E−01 −2.8860E−01  A6 = −6.0886E−02 1.9839E−02 8.9753E−02 3.1155E−01 A8 = −8.5385E−02 −4.7988E−02  −1.7743E−01−3.3495E−01  A10 =  7.5586E−02 2.7582E−02  1.5057E−01 2.5458E−01 A12 =−1.5883E−02 −6.1284E−03  −8.4192E−02 −1.1325E−01  A14 =  2.0751E−022.1213E−02 Surface # 10 11 12 13 k = −1.1289E+01 4.3508E+00 −3.8600E+015.3570E+00 A4 = −1.9500E−01 −4.4463E−02  −4.6507E−02 −4.8517E−02  A6 = 2.2713E−01 1.2179E−02 −2.2174E−02 4.0813E−03 A8 = −2.2484E−012.9818E−03  5.0590E−02 1.2076E−03 A10 =  1.7454E−01 −6.4288E−03 −3.4370E−02 −8.2087E−04  A12 = −7.7825E−02 2.2137E−03  1.1690E−021.7149E−04 A14 =  1.3541E−02 −2.5010E−04  −1.9837E−03 −1.1399E−05  A16 = 1.3282E−04 −2.0650E−07 

In the 7th embodiment, the equation of the aspheric surface profiles ofthe aforementioned lens elements is the same as the equation of the 1stembodiment. Also, the definitions of these parameters shown in the tablebelow are the same as those stated in the 1st embodiment withcorresponding values for the 7th embodiment, so an explanation in thisregard will not be provided again.

Moreover, these parameters can be calculated from TABLE 13 and TABLE 14and satisfy the conditions stated in the following table.

7th Embodiment f [mm] 5.87 BL/CT1 0.51 Fno. 1.45 tan(HFOV) 0.43 HFOV[deg.] 23.4 TL [mm] 6.61 (V2 + V4 + V6)/(V1 + V3) 0.60 SL/TL 0.71 (V4 +V5 + V6)/(V1 + V3) 0.69 f/TL 0.89 (CT2 + CT3 + CT4 + CT5)/(CT1 + CT6)0.49 EPD/ImgH 1.55 Σ AT/T34 1.32 Y11/ImgH 0.78 (R6 + R7)/(R6 − R7) −1.11Y11/Y62 0.94 (R11 − R12)/(R11 + R12) −0.23 Yc62/f 0.18 |f1/f3| 0.25TL/EPD 1.63 R1/CT1 1.28 f/EPD 1.45

The foregoing description, for purpose of explanation, has beendescribed with references to specific embodiments. It is to be notedthat TABLES 1-14 show different data of the different embodiments;however, the data of the different embodiments are obtained fromexperiments. The embodiments were chosen and described in order to bestexplain the principles of the disclosure and its practical applications,and thereby to enable others skilled in the art to best utilize thedisclosure and various embodiments with various modifications as aresuited to the particular use contemplated. The embodiments depictedabove and the appended drawings are exemplary and are not intended to beexhaustive or to limit the scope of the present disclosure to theprecise forms disclosed. Many modifications and variations are possiblein view of the above teachings.

What is claimed is:
 1. An optical imaging system comprising six lenselements, the six lens elements being, in order from an object side toan image side: a first lens element, a second lens element, a third lenselement, a fourth lens element, a fifth lens element and a sixth lenselement; wherein each of the six lens elements has an object-sidesurface facing toward the object side and an image-side surface facingtoward the image side, and at least one of the first through sixth lenselements comprises at least one inflection point; wherein a focal lengthof the optical imaging system is f, an axial distance between theobject-side surface of the first lens element and an image surface isTL, an entrance pupil diameter of the optical imaging system is EPD, anAbbe number of the first lens element is V1, an Abbe number of thesecond lens element is V2, an Abbe number of the third lens element isV3, an Abbe number of the fourth lens element is V4, an Abbe number ofthe sixth lens element is V6, and the following conditions aresatisfied:0.80<f/TL<1.10;1.0<f/EPD<1.55; and0.20<(V2+V4+V6)/(V1+V3)<0.80.
 2. The optical imaging system of claim 1,wherein the image-side surface of the six lens element is concave in aparaxial region thereof and has at least one convex shape in an off-axisregion thereof.
 3. The optical imaging system of claim 1, wherein theobject-side surface of the sixth lens element is convex in a paraxialregion thereof.
 4. The optical imaging system of claim 1, wherein theobject-side surface of the third lens element is convex in a paraxialregion thereof and the image-side surface of the third lens element isconcave in a paraxial region thereof.
 5. The optical imaging system ofclaim 1, wherein the first lens element has positive refractive power,the second lens element has negative refractive power, and the fifthlens element has negative refractive power.
 6. The optical imagingsystem of claim 1, wherein the axial distance between the object-sidesurface of the first lens element and the image surface is TL, theentrance pupil diameter of the optical imaging system is EPD, and thefollowing condition is satisfied:1.0<TL/EPD<1.90.
 7. The optical imaging system of claim 1, wherein a sumof axial distances between every two adjacent lens elements of theoptical imaging system is EAT, an axial distance between the third lenselement and the fourth lens element is T34, and the following conditionis satisfied:1.10<ΣAT/T34<2.50.
 8. The optical imaging system of claim 1, wherein avertical distance between a maximum effective diameter position on theobject-side surface of the first lens element and an optical axis isY11, a vertical distance between a maximum effective diameter positionon the image-side surface of the sixth lens element and the optical axisis Y62, and the following condition is satisfied:0.80<Y11/Y62<1.35.
 9. The optical imaging system of claim 1, wherein acentral thickness of the first lens element is CT1, a central thicknessof the second lens element is CT2, a central thickness of the third lenselement is CT3, a central thickness of the fourth lens element is CT4, acentral thickness of the fifth lens element is CT5, a central thicknessof the sixth lens element is CT6, and the following condition issatisfied:0.10<(CT2+CT3+CT4+CT5)/(CT1+CT6)<1.20.
 10. The optical imaging system ofclaim 1, wherein the sixth lens element has at least one inflectionpoint, the axial distance between the object-side surface of the firstlens element and the image surface is TL, and the following condition issatisfied:3.0 mm<TL<7.0 mm.
 11. The optical imaging system of claim 1, wherein anaxial distance between the third lens element and fourth lens element islarger than an axial distance between the fourth lens element and fifthlens element.
 12. An imaging apparatus, comprising the optical imagingsystem of claim 1 and an image sensor disposed on the image surface ofthe optical imaging system.
 13. An electronic device, comprising theimaging apparatus of claim
 12. 14. An optical imaging system comprisingsix lens elements, the six lens elements being, in order from an objectside to an image side: a first lens element, a second lens element, athird lens element, a fourth lens element, a fifth lens element and asixth lens element; wherein each of the six lens elements has anobject-side surface facing toward the object side and an image-sidesurface facing toward the image side, at least one of the first throughsixth lens elements comprises at least one inflection point; wherein afocal length of the optical imaging system is f, an axial distancebetween the object-side surface of the first lens element and an imagesurface is TL, an entrance pupil diameter of the optical imaging systemis EPD, an Abbe number of the first lens element is V1, an Abbe numberof the third lens element is V3, an Abbe number of the fourth lenselement is V4, an Abbe number of the fifth lens element is V5, an Abbenumber of the sixth lens element is V6, and the following conditions aresatisfied:0.80<f/TL<1.10;1.0<f/EPD<1.55; and0.30<(V4+V5+V6)/(V1+V3)<0.95.
 15. The optical imaging system of claim14, wherein the image-side surface of the fifth lens element is concavein a paraxial region thereof.
 16. The optical imaging system of claim14, wherein the sixth lens element has positive refractive power and theobject-side surface of the fifth lens element is concave in a paraxialregion thereof.
 17. The optical imaging system of claim 14, wherein theimage-side surface of the sixth lens element is concave in a paraxialregion thereof, a vertical distance between an off-axial critical pointon the image-side surface of the sixth lens element and an optical axisis Yc62, the focal length of the optical imaging system is f, and thefollowing condition is satisfied:0.05<Yc62/f<0.70.
 18. The optical imaging system of claim 14, whereinthe axial distance between the object-side surface of the first lenselement and the image surface is TL, the entrance pupil diameter of theoptical imaging system is EPD, and the following condition is satisfied:1.0<TL/EPD<1.90.
 19. The optical imaging system of claim 18, wherein theaxial distance between the object-side surface of the first lens elementand the image surface is TL, the entrance pupil diameter of the opticalimaging system is EPD, and the following condition is satisfied:1.0<TL/EPD≤1.63.
 20. The optical imaging system of claim 14, wherein avertical distance between a maximum effective diameter position on theobject-side surface of the first lens element and an optical axis isY11, a maximum image height of the optical imaging system is ImgH, andthe following condition is satisfied:0.65<Y11/ImgH<1.0.
 21. The optical imaging system of claim 14, wherein acurvature radius of the object-side surface of the sixth lens element isR11, a curvature radius of the image-side surface of the sixth lenselement is R12, and the following condition is satisfied:−0.10<(R11−R12)/(R11+R12)<0.35.
 22. The optical imaging system of claim14, wherein an axial distance between the image-side surface of thesixth lens element and the image surface is BL, a central thickness ofthe first lens element is CT1, and the following condition is satisfied:0.20<BL/CT1<0.90.
 23. The optical imaging system of claim 14, whereinthe axial distance between the third lens element and the fourth lenselement is the greatest among respective axial distances between everytwo adjacent lens elements of the optical imaging system.
 24. An opticalimaging system comprising six lens elements, the six lens elementsbeing, in order from an object side to an image side: a first lenselement, a second lens element, a third lens element, a fourth lenselement, a fifth lens element and a sixth lens element; wherein each ofthe six lens elements has an object-side surface facing toward theobject side and an image-side surface facing toward the image side, thesecond lens element has negative refractive power, and the sixth lenselement comprises at least one inflection point; wherein a focal lengthof the optical imaging system is f, an axial distance between theobject-side surface of the first lens element and an image surface isTL, an entrance pupil diameter of the optical imaging system is EPD, acurvature radius of the image-side surface of the third lens element isR6, a curvature radius of the object-side surface of the fourth lenselement is R7, and the following conditions are satisfied:0.80<f/TL<1.10;1.0<f/EPD<1.55; and−2.0<(R6+R7)/(R6−R7)<0.
 25. The optical imaging system of claim 24,wherein the entrance pupil diameter of the optical imaging system isEPD, a maximum image height of the optical imaging system is ImgH, andthe following condition is satisfied:1.15<EPD/ImgH<2.0.
 26. The optical imaging system of claim 24, whereinthe axial distance between the object-side surface of the first lenselement and the image surface is TL, the entrance pupil diameter of theoptical imaging system is EPD, and the following condition is satisfied:1.0<TL/EPD<1.90.
 27. The optical imaging system of claim 24, wherein acurvature radius of the object-side surface of the first lens element isR1, a central thickness of the first lens element is CT1, and thefollowing condition is satisfied:0.70<R1/CT1<1.50.
 28. The optical imaging system of claim 24, wherein acentral thickness of the sixth lens element is larger than a centralthickness of the fifth lens element.